Nitroazo dye and process of making same.



- UNITE i STATES Patented May 23, 1905.

, PATENT OFFICE.

JOHN HAGENBACH, OF BASEL, SWITZERLAND, ASSIGNOR TO ANILIN COLOR ANDEXTRACT WORKS FORMERLY J OHN R. GEIGY, OF BASEL,

SWITZERLAND.

NITROAZO DYE AND PROCESS OF MAKING SAME.

SPECIFICATION formingpart of Letters Patent No. 790,363, dated May 23,1905.

Application filed October 21,1904 Serial No. 229,416.

To all whom it may concern:

Be it known that I, J OHN HAeENBAoH,doctor of philosophy, a citizen ofthe Swiss Republic, and a resident of Basel, Switzerland, have in 5vented certain new and useful Improvements in Nitroazo Dyes andProcesses of Making Same, of which the following is a specification.

The nitration of diazo bodies without decomposition has never beeneifectuated with I success until now on account of their greatchangeableness. I have now found that the diazo body, which is obtainedfrom the l-amido-2-naphthol- L-sulfonic acid by diazoti'zing the latterin the presence of a neutral copper I5 salt as is described in thespecification for United States Letters Patent of T. Sandmeyer, SerialNo. 226,619, filed September 30, 1904, and in the German application, No. A1(),782 IV/12 dated March 4:, 1904:, can be 2 nitrated withoutdecomposition'in the well known manner, yielding a good crystallizingdurable nitrodiazo compound, which when coupled with beta-naphthol givesa novel and very valuable nitro ortho oxy azo coloringmatter, dyeingwool from acid-bath dark recldish brown, which shade after subsequenttreatment in the same bath with bichromate turns soot black,distinguished for an extremely great fastness .to the action of light 3and the processes of milling and potting. The facility with which thesaid diazo compound can be nitrated is probably based upon the characterof the non -nitrated diazo body, which against all expectation-andagainst all analogies is scarcely decomposable in its isolated and drystate. It can be dried without danger of explosion at a temperature offrom 80 to 100 centigrade, and also in dry state .it is not explosive.The reason for the ex- 4 ceptional behavior of this diazo bodymay beexplained by the supposition of an anhyrid form of the latter, asBamberger presumes in his publication (Ber. 03. D. 01mm. Goa, XXVII,page 680) for the non-sulfonated diazo-naphthols, naming them diazooxid. The effect of the nitro group in the combina tion of this nitrodiazo compound with betanaphthol is a very surprising one in two di'rections, first, the nitro group multiplies the tinctorial character ofthe thus-obtained coloring-matter and deepens the shade; secondly,it-increases theability of combination of the diazo compound in aconsiderable degree.

The following examples are given to illustrate the method of carryingout my invention. Example 1-Pr0ahwtc'0n 0 f nitro-1 -da20-2-7166])ILZILOZ-A-SQI/ZfORiO a0i0Z.Twenty-five kilos of Well-dried andpowdered l-diazo-Q-naphthol--sulfonic acid are, while stirring, addedgradually to seventy-five kilos of concentrated sulfuric acid. To this awell-cooled mixture of seven kilos of nitric acid (containing ninetysixper cent. real HNOaland fourteen kilos of monohydrate of sulfuric acidis allowed to runslowly while the temperature is kept between from O to5 centigrade by exterior cooling. To accomplish the reaction, thestirring is still continued 'for some hours at the same temperature.Then the whole is poured upon one hundred kilos of ice, broken in smallpieces. The nitro compound then separates immediately in the form ofslightly-yellow crystals, which are filtered ofi. The stillstrongly-acid paste of the thus-obtained nitrodiazo body is employeddirectly for the manufacture of the azo dyestuff. It is self-evidentthat the above-described process of nitration of the diazo-naphtholsulfonic acid. can be modified in different Ways with regard to theexact proportions, the temperature, and other 7 special conditionswithout alteration of the result. The nitro-l-diazo-Q-naphthol-4sulfonic acid or sulfonic acid of nitro-naphthalene-l-Q-diazoiixid thusobtained dissolves very easily in water with a yellow color and can beprecipitated from this solution by addition of moderately-dilutedsulfuric acid or concentrated hydrochloric acid in fine slightlyyellowcolored crystals.

Ermmple 2Mtr0-ae0 dye from nitro-1- (Ziaeo, 2- nap M/wl 4 sulfonic acid.Fifteen kilos of beta-naphthol are dissolved in two hundred liters ofwater by addition of fourteen kilos of caustic-soda lye of 40 Baum. Thenare added fifty kilos of sodium carbonate dissolved in one hundred andfifty liters of water. To this solution is carried in the acid paste ofthe nitro-diazo compound, directly obtained by nitration of twenty-fivekilos diazonaphtholsulfonic acid, according to the foregoing Example 1,in small portions, and the temperature kept at about 25 centigrade. Theformation of the color begins almost instantaneously; but itisaccomplished only after several hours and may be known acid to theWatery solution a reddish brown precipitate separates.

Having now described my invention, what I claim is 1.'lheherein-described process for the manufacture of a new nitro-azodyestufi', which consists in nitrating the naphthalene-l-Z-diazooxid-et-sulfonic acid, and combining the thusobtained nitro-diazocompound with betanaphthol, substantially as set forth.

2. The herein-described process for the production of nitronaphthalene-1-2-diazo oxid-isulfonic acid, which consists in nitratingthe naphthalene-l-Q-diazo oxidi-sulfonic acid, substantially as setforth.

3. The new nitro-azo dyestuff produced by combining thenitro-naphthalene1 -2diazo oxid-L-sulfonic acid with beta-naphthol,being in form of its sodium salt a brownishblack powder with metallicluster easily soluble in water with a dark-blue color, separating areddish-brown precipitate on addition of a mineral acid, and dyeing awool from acidbath dark reddish brown,which shade by after treatmentwith bichromate changes into sootblack, extremely fast to light and theprocesses of milling and potting substantially as set forth.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

JOHN HAGENBAGH.

Vitnesses:

Gno. GIFFORD, ALBERT GRASLER.

